explain_accept4(3)

💖 explain_accept4 — explain accept4(2) errors 💖

okay bestie, welcome to explain_accept4(3) from the Library Functions Manual, aka the little glow-up your error messages have been begging for. this page is part of libexplain, and it's literally here to turn a cryptic accept4(2) failure into a whole explanation. no cap. 🦋

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🌸 SYNOPSIS 🌸

#include <libexplain/accept4.h>
const char *explain_accept4(int fildes, struct sockaddr *sock_addr,
        socklen_t *sock_addr_size, int flags);
const char *explain_errno_accept4(int errnum, int fildes, struct
        sockaddr *sock_addr, socklen_t *sock_addr_size, int flags);
void explain_message_accept4(char *message, int message_size, int
        fildes, struct sockaddr *sock_addr, socklen_t *sock_addr_size, int
        flags);
void explain_message_errno_accept4(char *message, int message_size, int
        errnum, int fildes, struct sockaddr *sock_addr, socklen_t
        *sock_addr_size, int flags);

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✨ DESCRIPTION ✨

these functions are your emotional support besties for when accept4(2) returns an error and you're sitting there like "ma'am, what". you use them to obtain explanations for errors returned by the accept4(2) system call. periodt. 💅

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🎀 explain_accept4

const char *explain_accept4(int fildes, struct sockaddr *sock_addr,
socklen_t *sock_addr_size, int flags);

the explain_accept4 function is used to obtain an explanation of an error returned by the accept4(2) system call. the least the message will contain is the value of strerror(errno), but usually it will do much better and indicate the underlying cause in more detail. it's giving overachiever, in the best way. 👑

the errno global variable will be used to obtain the error value to be decoded.

• fildes — the original fildes, exactly as passed to the accept4(2) system call.
• sock_addr — the original sock_addr, exactly as passed to the accept4(2) system call.
• sock_addr_size — the original sock_addr_size, exactly as passed to the accept4(2) system call.
• flags — the original flags, exactly as passed to the accept4(2) system call.

Returns: the message explaining the error. this message buffer is shared by all libexplain functions which do not supply a buffer in their argument list. this will be overwritten by the next call to any libexplain function which shares this buffer, including other threads. 😭

Note: this function is not thread safe, because it shares a return buffer across all threads, and many other functions in this library. bestie, do not trust it with your threads. 💀

Example: this function is intended to be used in a fashion similar to the following example:

int result = accept4(fildes, sock_addr, sock_addr_size, flags);
if (result < 0)
{
    fprintf(stderr, "%s\n", explain_accept4(fildes, sock_addr,
    sock_addr_size, flags));
    exit(EXIT_FAILURE);
}

the above code example is available pre‐packaged as the explain_accept4_or_die(3) function. slay, someone already did the work for you. 🫶

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🌈 explain_errno_accept4

const char *explain_errno_accept4(int errnum, int fildes, struct
sockaddr *sock_addr, socklen_t *sock_addr_size, int flags);

the explain_errno_accept4 function is used to obtain an explanation of an error returned by the accept4(2) system call. the least the message will contain is the value of strerror(errno), but usually it will do much better, and indicate the underlying cause in more detail. iconic behavior fr fr. ✨

• errnum — the error value to be decoded, usually obtained from the errno global variable just before this function is called. this is necessary if you need to call any code between the system call to be explained and this function, because many libc functions will alter the value of errno. yes, they really will. watch out. 🙈
• fildes — the original fildes, exactly as passed to the accept4(2) system call.
• sock_addr — the original sock_addr, exactly as passed to the accept4(2) system call.
• sock_addr_size — the original sock_addr_size, exactly as passed to the accept4(2) system call.
• flags — the original flags, exactly as passed to the accept4(2) system call.

Returns: the message explaining the error. this message buffer is shared by all libexplain functions which do not supply a buffer in their argument list. this will be overwritten by the next call to any libexplain function which shares this buffer, including other threads.

Note: this function is not thread safe, because it shares a return buffer across all threads, and many other functions in this library. 💀

Example: this function is intended to be used in a fashion similar to the following example:

int result = accept4(fildes, sock_addr, sock_addr_size, flags);
if (result < 0)
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_accept4(err, fildes,
    sock_addr, sock_addr_size, flags));
    exit(EXIT_FAILURE);
}

the above code example is available pre‐packaged as the explain_accept4_or_die(3) function. 🎀

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🦋 explain_message_accept4

void explain_message_accept4(char *message, int message_size, int
fildes, struct sockaddr *sock_addr, socklen_t *sock_addr_size, int
flags);

the explain_message_accept4 function is used to obtain an explanation of an error returned by the accept4(2) system call. the least the message will contain is the value of strerror(errno), but usually it will do much better, and indicate the underlying cause in more detail. it's the "please explain" of the group chat. 💬

the errno global variable will be used to obtain the error value to be decoded.

• message — the location in which to store the returned message. if a suitable message return buffer is supplied, this function is thread safe. main character energy, honestly. 👑
• message_size — the size in bytes of the location in which to store the returned message.
• fildes — the original fildes, exactly as passed to the accept4(2) system call.
• sock_addr — the original sock_addr, exactly as passed to the accept4(2) system call.
• sock_addr_size — the original sock_addr_size, exactly as passed to the accept4(2) system call.
• flags — the original flags, exactly as passed to the accept4(2) system call.

Example: this function is intended to be used in a fashion similar to the following example:

int result = accept4(fildes, sock_addr, sock_addr_size, flags);
if (result < 0)
{
    char message[3000];
    explain_message_accept4(message, sizeof(message), fildes,
    sock_addr, sock_addr_size, flags);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

the above code example is available pre‐packaged as the explain_accept4_or_die(3) function. 🔥

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💜 explain_message_errno_accept4

void explain_message_errno_accept4(char *message, int message_size, int
errnum, int fildes, struct sockaddr *sock_addr, socklen_t
*sock_addr_size, int flags);

the explain_message_errno_accept4 function is used to obtain an explanation of an error returned by the accept4(2) system call. the least the message will contain is the value of strerror(errno), but usually it will do much better, and indicate the underlying cause in more detail. bestie this one has everything — buffer and errno. a whole meal. 🍓

• message — the location in which to store the returned message. if a suitable message return buffer is supplied, this function is thread safe.
• message_size — the size in bytes of the location in which to store the returned message.
• errnum — the error value to be decoded, usually obtained from the errno global variable just before this function is called. this is necessary if you need to call any code between the system call to be explained and this function, because many libc functions will alter the value of errno. noted and memorized. 📝
• fildes — the original fildes, exactly as passed to the accept4(2) system call.
• sock_addr — the original sock_addr, exactly as passed to the accept4(2) system call.
• sock_addr_size — the original sock_addr_size, exactly as passed to the accept4(2) system call.
• flags — the original flags, exactly as passed to the accept4(2) system call.

Example: this function is intended to be used in a fashion similar to the following example:

int result = accept4(fildes, sock_addr, sock_addr_size, flags);
if (result < 0)
{
    int err = errno;
    char message[3000];
    explain_message_errno_accept4(message, sizeof(message), err,
    fildes, sock_addr, sock_addr_size, flags);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

the above code example is available pre‐packaged as the explain_accept4_or_die(3) function. 🧚

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⭐ SEE ALSO ⭐

• accept4(2) — accept a connection on a socket
• explain_accept4_or_die(3) — accept a connection on a socket and report errors

iykyk, these two are the duo. 🌈

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💅 COPYRIGHT 💅

this whole page is from libexplain version 1.4, and the copyright belongs to Copyright (C) 2009 Peter Miller.

that's it, that's the page — go forth and let your errors explain themselves, bestie. stay hydrated, stay thread-safe (or at least use the buffer versions 💖), and remember: explain_accept4_or_die(3) is always there for you. periodt. 👑✨